html {
    overflow: hidden
}

html, body{
    height: 100%
}

body{
    overflow: hidden;
    overflow-y: auto;
    -webkit-perspective: 1px;
    -moz-perspective: 1px;
    perspective: 1px;
    -webkit-transform-style: preserve-3d;
    -moz-transform-style: preserve-3d;
    transform-style: preserve-3d
}

.parallax-container{
    /* Define the height of the container
    where the image will be */
    height:400px
}

.parallax-img{
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background-image:url('background-img.jpg');
    background-position: center top; 
    background-size: cover;
    -webkit-transform: translateZ(-1px) scale(2);
    -moz-transform: translateZ(-1px) scale(2);
    transform: translateZ(-1px) scale(2);
    z-index: -99
}